Power Electronics SD700FL Series, Руководство по аппаратному обеспечению и установке

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SD700FL SERIES
POWER ELECTRONICS
28
POWER CONNECTION
6.2. Topology
SD700FL drive operates according to the principle of pulse-width modulation (PWM). Varying the
motor‟s
output voltage and the frequency, it is possible to control the speed and torque of the connected induction
three-phase motors by means of its main components: rectifier bridge, the DC bus, inverter bridge, and
power and control board.
Figure 6.2 General Block Scheme for frames 3 to 11
SD700FL drives are composed as an SD700 VFD and a Freemaq filter.
Freemaq filters are installed in the input of the SD700 VFD and reduce significantly the THDi values, and
increase the impedance line protecting the drive against electrical distortions.
SD700 integrate as standard input chokes filters. These filters reduce significantly the THDi values, and
increase the impedance line protecting the drive against electrical distortions. Depending on the frame, the
input choke filter is installed in the input side or in the DC bus. For frames 3 to 11, filter is installed in the
input side. For frames 1 and 2, filter is installed in the DC bus (see figure 6.3).
SD700 frames 5 to 11 integrate as standard ultra fast fuses that protect the drive against downstream
overcurrents. Additionally the drive integrates multiple electrical protections that protect the drive and the
motor as a motor relay does.
The SD700FL
includes a power and a control board to control the rectifier thyristor diode‟s bridge shooting,
the
inverter IGBT‟s bridge shooting, the soft charge, the DC bus voltage and the motor performance. In
addition, control board integrates the interface terminals such as communication ports, the digital and
analogue inputs and outputs, colour touch-screen display and alphanumeric display, etc. The Freemaq
filter is managed from the SD700; specifically SD700 activates the fans and the contactor of the capacitors
bank. In the other hand, filters inform the SD700 if someone is overheated.
The inverter bridge generates the PWM wave that controls the motor performance (voltage, current,
torque, etc...). SD700FL Series by Power Electronics, integrate as standard output dV/dt filters and a
CLAMP system that reduces significantly the dV/dt rise time below 500V/μs - 800V/μs, therefore, it
reduces the voltages peaks at the motor windings, the common mode currents and the EMC emissions.
Depending on the power of the SD700FL drive, one to nine filter cabinet modules compose the filter. The
filters have been designed to cover the whole range of the SD700 family. The following figures show the
general connection of a single module filter and a three modules Freemaq parallel connection.
When the SD700FL is composed of more than 5 filter modules, it will be delivered separately. That means,
in one hand the filters and in the other the VFD. The modules are internally wired and the user has only to
make the connections between the VFD and the reference filter. The reference filter is always the nearest
filter to the VFD.